Each robot teaching pendant is usually provided with an operator panel for teaching, character-based display device, etc. The robot is taught and operated by using such teaching pendants while watching the motion of a robot arm.
Such a character-based display device is capable of displaying only alphabet letters, figures, Chinese characters, and Japanese characters but not capable of graphically displaying the spatial relations among taught points and the like, su that it is difficult for an operator to have intuitive recognitions. Although the spatial position and motion of the robot arm are expected to be displayed graphically, they can be expressed only in numerical values or the like. Thus, it has been no easy matter for the operator to operate the robot using a robot teaching pendant.